Seal ring is to give strength to the die, and scribe line is margin for wafer cutting. Rough figures are abt 15u from pad, all sides (combining sealreing & scribline)
this term is used with respect to the wafer and not a single die ... so u might not get much info on this in blast fusion etc., apart from the die size decided for a chip, a clearance figure of few microns are added around the die size so that the various adjacent dies can be cut from the wafer.. this is however a very crude explanation of the same... might not be very technical!!